摘要：
Summer-autumn tea leaves are abundant, yet their utilization remains low. Our study enhances the quality and flavor of Golden Flower loose tea (GFLT) from fresh summer-autumn tea leaves by using a special "Golden Flower" fungus (strain ACF-2). The strain ACF-2, identified as Aspergillus cristatus with yellow cleistothecium and isolated from Fu Brick Tea, was characterized by colony morphology, microstructural analyses, and phylogenetic examination using a 3-gene dataset (BenA, CaM, RPB2). Inoculation of raw dark tea products with A. cristatus led to a significant increase in tea water extract and a reduction in tea polyphenols, soluble sugars, flavonoids, and total amino acids, thereby enhancing the quality and flavor of GFLT. HS-SPME-GC-MS analysis of GFLT aroma revealed that A. cristatus substantially improved the tea's aroma profile. 9 volatile compounds-(Z)-jasmone I, beta-cyclocitral, linalool oxide I, linalool, hexanal, 1-octen-3-ol, (Z)-citral, citral, and methyl salicylate, were found to be significantly elevated in GFLT compared to the controls. Our findings provide both theoretical and practical insights into optimizing the utilization of summer-autumn tea leaves, identifying the "Golden Flower" fungus, and understanding its impact on GFLT quality. In summary, fermenting A. cristatus to produce GFLT may be a new channel to utilize summer-autumn tea.
通讯作者：
Jian'an Huang<&wdkj&>Zhonghua Liu<&wdkj&>Jian'an Huang Jian'an Huang Jian'an Huang<&wdkj&>Zhonghua Liu Zhonghua Liu Zhonghua Liu
作者机构：
[Hongzhe Zeng; Kuofei Wang; Changwei Liu; Jie Ouyang; Shuai Wen; Fang Zhou; Jingyi Tang; Wenwen Fang; Lin Yue; Jian'an Huang; Zhonghua Liu; Hongzhe Zeng Hongzhe Zeng Hongzhe Zeng; Kuofei Wang Kuofei Wang Kuofei Wang; Changwei Liu Changwei Liu Changwei Liu; Jie Ouyang Jie Ouyang Jie Ouyang; Shuai Wen Shuai Wen Shuai Wen; Fang Zhou Fang Zhou Fang Zhou; Jingyi Tang Jingyi Tang Jingyi Tang; Wenwen Fang Wenwen Fang Wenwen Fang; Lin Yue Lin Yue Lin Yue; Jian'an Huang Jian'an Huang Jian'an Huang; Zhonghua Liu Zhonghua Liu Zhonghua Liu] Key Laboratory of Tea Science of Ministry of Education, National Research Center of Engineering and Technology for Utilization of Botanical Functional Ingredients, Co-Innovation Center of Education Ministry for Utilization of Botanical Functional Ingredients, Key Laboratory for Evaluation and Utilization of Gene Resources of Horticultural Crops, Ministry of Agriculture and Rural Affairs of China, Hunan Agricultural University, Changsha, China
通讯机构：
[Jian'an Huang; Zhonghua Liu; Jian'an Huang Jian'an Huang Jian'an Huang; Zhonghua Liu Zhonghua Liu Zhonghua Liu] K;Key Laboratory of Tea Science of Ministry of Education, National Research Center of Engineering and Technology for Utilization of Botanical Functional Ingredients, Co-Innovation Center of Education Ministry for Utilization of Botanical Functional Ingredients, Key Laboratory for Evaluation and Utilization of Gene Resources of Horticultural Crops, Ministry of Agriculture and Rural Affairs of China, Hunan Agricultural University, Changsha, China
摘要：
(1) This study may be the first study to evaluate the effects of oolong tea with different storage time in db/db T2DM mice.(2) All three aged oolong tea extracts (2001, 2011, 2020) can effectively alleviate type 2 diabetes mellitus (T2DM), and 2011 aged oolong tea extract exhibited relatively optimal ability to alleviate T2DM.(3) With storage time of oolong tea increasing, oolong tea’s ability to inhibit fat ectopic deposition in liver increases and the ability to activate INSR/IRS/PI3K/AKT/GSK‐3β/GYS‐mediated hepatic glycogen synthesis signaling pathway decreases. Abstract An important concern for tea consumers is whether appropriate storage can effectively improve the ability of oolong tea to alleviate type 2 diabetes mellitus (T2DM). In this study, the antidiabetic effects of three aged oolong tea (2001, 2011, and 2020) extracts (aged TEs) in db/db T2DM mice were investigated and compared for the first time. The results showed that aged oolong tea extracts (aged TEs) alleviated the abnormal fasting blood glucose levels, lipid profiles, insulin resistance, and reduced ectopic fat deposition in liver. Moreover, aged TEs alleviated T2DM‐related tissue damage and activated insulin receptor (INSR)/insulin receptor substrate (IRS)/phosphatidylinositol‐3 kinase (PI3K)/phosphatidylinositol‐3 kinase (AKT)/glycogen synthase kinase 3 beta (GSK‐3β)/glycogen synthase (GYS)‐mediated hepatic glycogen synthesis signaling pathway. In addition, aged TEs altered gut microbiota composition and gut metabolite profiles associated with T2DM. Together, all three aged TEs (400 mg/kg/day in mice, a human equivalent dose of 7 g/60 kg/day), especially 2011, can effectively alleviate T2DM, and proper storage can effectively improve the ability of oolong tea to alleviate T2DM.
摘要：
The objective of this study is to explore the influence of extraction factors, including extraction temperatures, extraction time, and tea-water ratios, on the sensory quality and aroma characteristics of instant Pu-erh tea (IPET). Sensory evaluation, quantitative descriptive analysis (QDA) and HS-SPME-GC x GC-TOF/MS were utilized for analysis. The result showed that the optimal process condition of IPET was a tea-to-water ratio 1:8, an extraction temperature 75 C-degrees, and an extraction time 60 min. A total of 235 volatile compounds were identified and 65 key odor-active compounds with ROAV>1 in all samples. Based VIP > 1, 19 key differential odor-active compounds were identified, including linalool oxide I, 1-dodecanol, linalool oxide II, etc. Further Pearson correlation analysis of key differential odor-active compounds and aroma characteristics showed that positive correlations between woody and ethyl nonanoate and 1-dodecanol, and between herbal and 1-methylnaphthalene. This research provides theoretical support for the production of high-quality IPET.
摘要：
Liquid chromatography-mass spectrometry (LC-MS) combined with multivariate analysis were used to characterize the nonvolatile compounds of broken green tea and explore the effect of isolated scenting on metabolic profile and taste quality of broken green tea in this research. A total of 236 nonvolatile compounds were identified and 13 compounds were believed to be the key characteristic taste compounds of scented broken green tea. Meanwhile, the optimal isolated scenting time of broken green tea was determined to be 10h based on the sensory evaluation and PLS results. The contents and types of flavonoids, organic acids and catechins lead to the difference of taste quality at different scenting times. Overall, these findings provided a theoretical basis for scenting to improve the taste of broken green tea, and provide a new idea for improving the taste of broken green tea.
摘要：
Background: Qingzhuan tea (QZT) is classified as compressed dark tea and has been an essential daily commodity for ethnic minority communities in China 's border areas. It boasts unique flavor characteristics and health benefits, captivating the attention of consumers both domestically and internationally. However, the QZT industry 's historical closed nature and lengthy processing cycle have impeded a comprehensive scientific understanding and evaluation of this tea, as well as hindered the overall healthy development of the industry. Scope and approach: This article provides a comprehensive overview of the research progress on QZT, covering defluoridation techniques, processing technology, flavor characteristics, chemical composition, microbial communities, health benefits, and their underlying mechanisms. Key findings and conclusions: A technology system aimed at reducing fluoride levels in tea, known as "appropriate fertilization -selection of low -fluorine tea tree varieties -control of raw material tenderness and growing period, " has been proposed. Through the implementation of specific processing techniques, QZT exhibiting an orange -red infusion color, a mellow taste, and an aged aroma. During the key pile fermentation process, microorganisms release extracellular enzymes that initiate enzymatic and moist heat reactions, resulting in oxidation, hydrolysis, polymerization, and secondary metabolic conversions. These reactions serve as the underlying foundation for the distinctive sensory attributes of QZT. The regulation of microorganisms plays a vital role in attaining the desired flavor of QZT. Moreover, QZT encompasses a diverse array of bioactive constituents, which offer numerous health advantages such as antioxidative properties, anti -obesity and anti -diabetes effects, modulation of the intestinal microbiota, and alleviation of non-alcoholic fatty liver.
摘要：
Drying is the final and essential step in tea processing. It contributes a lot to the formation of tea flavor quality by a series of complicated and violent thermochemical reactions, such as degradation reaction, Maillard reaction, redox reaction, isomerization reaction, etc. However, the mechanism of specific thermochemical reaction is unclear. Here, by comprehensively summarizing the thermochemical reactions of the main chemicals, including polyphenols, lipids, amino acids and carbohydrates, etc., during tea drying with particularly focus on their contributions of thermal drying on the flavor including color, aroma, and taste, we found that thermal degradation is the dominant thermochemical reaction, directly affecting the taste and color of tea, and thermal oxidation of lipids and Maillard reaction mainly contribute to form tea aroma. More interesting was that high temperature enhanced nucleophilicity of phenolics, allowing them to easily trap carbonyl substances to form small molecular adducts (i.e. EPSFs) or polymers, which could interfere other thermochemical reactions, and then alter the flavor quality of tea. Over all, this review provides updated scientific evidence for in-depth exploration of thermochemical reactions towards tea precision processing.
关键词：
Black tea;Hypoglycemic activity;Interaction mechanism;Theaflavins;α-amylase
摘要：
Hyperglycemia can cause early damage to human bady and develop into diabates that will severely threaten human healthy. The effectively clinical treatment of hyperglycemiais is by inhibiting the activity of alpha-amylase. Black tea has been reported to show inhibitory effect on alpha-amylase and can be used for hyperglycemia treatment. However, the mechanism underlying is unclear. In this study, in vivo experiment showed that black tea theaflavins extract (BTE) effectively alleviated hyperglycemia. In vitro experiment showed that the effects may be caused by the interation between theaflavins and alpha-amylase. While TF1 and TF3 were mixed type inhibitors of alpha-amylase, TF2A and TF2B were competitive inhibitors of alpha-amylase. Molecular docking analysis showed that theaflavins monomers interacted with the hydrophobic region of alpha-amylase. Further study verified that monomer-alpha-amylase complex was spontaneously formed depending on hydrophobic interactions. Taken together, theaflavins showed potential anti-hyperglycemia effect via inhibiting alpha-amylase activity. Our results suggested that theaflavins might be utilized as a new type of alpha-amylase inhibitor to prevent and cure hyperglycemia.
摘要：
Yellow tea is a lightly fermented tea with unique sensory qualities and health benefits. However, chemical composition and sensory quality of yellow tea products have rarely been studied. 12 representative yellow teas, which were basically covered the main products of yellow tea, were chosen in this study. Combined analysis of non-targeted/targeted metabolomics and electronic sensor technologies (E-eye, E-nose, E-tongue) revealed the chemical and sensor variation. The results showed that yellow big tea differed greatly from yellow bud teas and yellow little teas, but yellow bud teas could not be effectively distinguished from yellow little teas based on chemical constituents and electronic sensory characteristics. Sensor variation of yellow teas might be attributed to some compounds related to bitterness and aftertaste-bitterness (4'-dehydroxylated gallocatechin-3-O-gallate, dehydrotheasinensin C, myricitin 3-O-galactoside, phloroglucinol), aftertaste-astringency (methyl gallate, 1,5-digalloylglucose, 2,6-digalloylglucose), and sweetness (maltotriose). This study provided a comprehensive understanding of yellow tea on chemical composition and sensory quality.
摘要：
Obesity is associated with gut dysbiosis and metabolic endotoxin. Junshanyinzhen tea extract ( JSTE) reduced fat accumulation and body weight in obese mice. However, the effects and mechanism of JSTE in preventing obesity were unclear. Therefore, we used different doses of JSTE (75, 150 and 300 mg/(kg<middle dot>day)) to evaluate the effect on high-fat diet (HFD)-induced rats under 8 weeks of intervention. Here, our results showed that JSTE could significantly reduce body weight gain, blood lipid levels and fat accumulation, improve fatty damage in liver tissue (P < 0.05). In addition, JSTE increased the expression of intestinal tight junction proteins (P < 0.05), relieved metabolic endotoxemia (P < 0.05) and chronic low-grade inflammation in HFD rats. Sequencing of fecal samples showed that JSTE could effectively reverse the microbial diversity and the ratio of Firmicutes to Bacteroidetes to normal levels in HFD-fed rats. Desulfovibrioceae and Erysipelotrichaceae, which are positively related to obesity, were decreased by JSTE intervention (P < 0.05). while Bifidobacteriaceae, Bacteroidaceae, Akkermansia, and Clostridium, which are negatively related to obesity, were increased. Together, these results suggested that JSTE might effectively prevent obesity by modulating gut microbiota dysbiosis, intestinal barrier dysfunction, metabolic endotoxemia and chronic lowgrade inflammation in HFD-induced rats. (c) 2024 Beijing Academy of Food Sciences. Publishing services by Tsinghua University Press. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).
关键词：
Fu Brick Tea;Sensomics analysis;Aroma recombination and omission;Key odor-active compounds;Bacterial community
摘要：
Fu Brick Tea (FBT) is a unique fermented tea produced in multiple regions of China, whose aroma qualities, key odor-active compounds and bacterial communities are not well characterized. By optimizing HS-SPME methods, utilizing GC-MS, GC-O, sensory analysis, aroma recombination and omission experiments, and bacterial sequencing, we revealed the primary volatiles and bacterial communities in 41 samples from 7 major producing regions. A total of 63 volatiles and 32 odor-active compounds were quantitatively analyzed using GC-MS and GC-O, respectively. Sensory analyses discriminated the quality of the samples. Differential analysis indicated that poor aroma FBTs had either low volatile content or excessive "green" notes. Key odor-active compounds in highquality aroma FBTs include 1-octen-3-ol, phenylethylalcohol, beta-ionone, dihydroactindiolide, and 1,2,3-trimethoxybenzene. Sequencing results identified Bacillus, Pseudomonas, and Streptococcus as dominant genera. Functional prediction analyses suggest that bacteria contribute to the formation of FBT aroma. This study offers new insights into the quality characteristics of FBT.
通讯机构：
[Yin, X ; Liu, ZH ] H;Hunan Agr Univ, Key Lab Tea Sci, Minist Educ, Changsha 410128, Peoples R China.;Natl Res Ctr Engn & Technol Utilizat Bot Funct Ing, Changsha 410128, Peoples R China.;Hunan Acad Agr Sci, Tea Res Inst, Dept Tea Qual Chem & Nutr Hlth, Hunan Tea Plant & Tea Proc Observat Stn,Minist Agr, Changsha 410125, Peoples R China.;Minist Utilizat Bot Funct Ingredients, Coinnovat Ctr Educ, Changsha 410128, Peoples R China.
关键词：
shaken Hunan black tea;leaves grade;taste;aroma;HS-SPME/GC-MS
摘要：
<jats:p>Shaken Hunan black tea is an innovative Hunan black tea processed by adding shaking to the traditional Hunan black tea. The quality of shaken black tea is influenced by leaf grades of different maturity. In this study, the taste and aroma quality of shaken Hunan black tea processed with different grades were analyzed by sensory evaluation (SP, HPLC, and HS-SPME/GC-MS). The results showed that shaken Hunan black tea processed with one bud and two leaves has the best quality, which has a sweet, mellow, and slightly floral taste, as well as a floral, honey, and sweet aroma. Moreover, caffeine and EGCG were identified as the most important bitter and astringent substances in shaken Hunan black. Combined with the analysis of GC-MS and OAV analysis, geraniol, jasmone, β-myrcene, citral, and trans-β-ocimene might be the most important components that affect the sweet aroma, while methyl jasmonate, indole, and nerolidol were the key components that affect the floral aroma of shaken Hunan black tea. This study lays a foundation for this study of the taste and aroma characteristics of shaken Hunan black tea and guides enterprises to improve shaken black tea processing technology.</jats:p>
摘要：
Recently, research has confirmed that jasmine tea may help improve the depressive symptoms that are associated with psychiatric disorders. Our team previously found that jasmine tea improved the depressive-like behavior that is induced by chronic unpredictable mild stress (CUMS) in Sprague Dawley (SD) rats. We hypothesized that the metabolic disorder component of depression may be related to the gut microbiota, which may be reflected in the metabolome in plasma. The influence of jasmine tea on gut microbiota composition and the association with depressive-related indexes were explored. Furthermore, the metabolites in plasma that are related to the gut microbiota were identified. SD rats were treated with control or CUMS and administrated jasmine tea for 8 weeks. The 16S rRNA gene amplicon sequencing was used to analyze the gut microbiota in feces samples, and untargeted metabolomics was used to analyze the metabolites in plasma. The results found that jasmine tea significantly ameliorated the depressive behavior induced by CUMS, significantly improved the neurotransmitter concentration (BDNF and 5-HT), and decreased the pro-inflammation levels (TNF-α and NF-κB). The intervention of jasmine tea also alleviated the dysbiosis caused by CUMS; increased the relative abundance of Bacteroides, Blautia, Clostridium, and Lactobacillus; and decreased Ruminococcus and Butyrivibrio in the CUMS-treated rats. Furthermore, the serum metabolites of the CUMS-treated rats were reversed after the jasmine tea intervention, i.e., 22 were up-regulated and 18 were down-regulated, which may have a close relationship with glycerophospholipid metabolism pathways, glycine serine and threonine metabolism pathways, and nicotinate and nicotinamide metabolism pathways. Finally, there were 30 genera of gut microbiota related to the depressive-related indexes, and 30 metabolites in the plasma had a strong predictive ability for depressive behavior. Potentially, our research implies that the intervention of jasmine tea can ameliorate the depression induced by CUMS via controlling the gut flora and the host's metabolism, which is an innovative approach for the prevention and management of depression.
摘要：
Phyllosphere microorganisms have recently attracted the attention of scientists studying plant microbiomes. The origin, diversity, functions, and interactions of phyllosphere microorganisms have been extensively explored. Many experiments have demonstrated seasonal cycles of phyllosphere microbes. However, a comprehensive comparison of these separate investigations to characterize seasonal trends in phyllosphere microbes of woody and herbaceous plants has not been conducted. In this review, we explored the dynamic changes of phyllosphere microorganisms in woody and non-woody plants with the passage of the season, sought to find the driving factors, summarized these texts, and thought about future research trends regarding the application of phyllosphere microorganisms in agricultural production. Seasonal trends in phyllosphere microorganisms of herbaceous and woody plants have similarities and differences, but extensive experimental validation is needed. Climate, insects, hosts, microbial interactions, and anthropogenic activities are the diverse factors that influence seasonal variation in phyllosphere microorganisms.
摘要：
In this study, non-covalent binding mechanism of lactoferrin (LaF)-theaflavin (TF) complex and its functional properties were investigated. Multi-spectroscopic analyses showed that the secondary structure of LaF was altered with increasing TF concentration. The non-covalent binding of TF to LaF resulted in a reduction in the content of the alpha-helix and beta-sheet, as well as a decrease in the fluorescence intensity of LaF. DSC result showed that non-covalent binding of TF improved thermal stability of LaF. Molecular dynamics simulations confirmed that the stable binding of LaF-TF was driven by hydrogen bonding and hydrophobic interactions. Additionally, non-covalent binding of TF increased the antioxidant capacity and emulsifying properties of LaF. Dynamic interfacial tension indicated that the strong interaction between LaF and TF reduced the interfacial tension, but improved the rheological properties of LaF. The functional characteristics of the non-covalent complex was effectively enhanced, paving the way for its potential use in the food industry.
摘要：
Background: Selenium is an essential trace element for human health and its deficiency leads to increased risk of many diseases worldwide. Tea (Camellia sinensis (L.) O. Kuntze) is a plant with selenium accumulation ability. Selenium-enriched tea combines the flavor and health benefits of tea with the additional wellness advantages of selenium, holding promising market potential. Scope and approach: This article reviews the latest research advances on selenium-enriched tea. The ability and mechanism of selenium accumulation in tea plants, as well as the existence forms of selenium in tea leaves, have been summarized. In addition, we examined the effects of selenium on tea physiological activities, including metabolic and quality regulation, and provided a summary of the associated health benefits. Key findings and conclusions: Tea plants possess a strong ability to accumulate selenium in selenium-rich area or under selenium fertilizer application. Over 80% of the selenium in selenium-enriched tea leaves exists in organic forms, including selenoamino acids, selenoproteins, selenium-polysaccharides, and selenium-polyphenols. Selenium can promote tea growth and optimize the proportion of quality compounds (e.g., polyphenols, amino acids, and alkaloids). The levels of stress-related antioxidant enzymes and phytohormones are increased to promote environmental stress resistance and selenium tolerance. Selenium-enriched tea demonstrates superior health benefits compared to regular tea due to the synergistic effects of tea active ingredients and selenium element. This review aims to inspire innovative ideas for the development of selenium-enriched tea with thriving growth conditions, high selenium bioaccessibility, delightful flavor, and broad applications in the food and health industries.
摘要：
Catechins, among the most active components in tea, effectively alleviate obesity. Catechins are primarily classified into four types based on the presence or absence of the C-3 galloyl group and the B-5' hydroxyl group. However, the impact of conformation on the anti-obesity properties of catechins remains unclear. Findings indicate that the C-3 galloyl group and the B-5' hydroxyl group significantly enhance the biological activity of catechins, aiding in obesity alleviation, regulating glycolipid metabolism, reducing hepatic steatosis, lowering serum lipopolysaccharide (LPS) levels, and promoting the proliferation of Akkermansia muciniphila. Further investigation revealed that Akkermansia muciniphila may modulate LPS/insulin resistance to protect glycolipid metabolic homeostasis, attenuate liver tissue damage, and promote catechin metabolism to generate new bioactive components. Overall, the C-3 galloyl group and the B-5' hydroxyl group may modulate the gut-liver axis through the bidirectional interplay between catechins and Akkermansia muciniphila, thereby enhancing the anti-obesity activity of catechins.
摘要：
Background: Theaflavins (TFs) are orange-red pigments with a benzotropolone structure, which are formed by the polymerization of catechins under oxidase-catalysed oxidation in the fermentation stage of black tea production. The contents of TFs play a crucial role in determining the sensory properties and commercial value of black tea. As natural bioactive compounds, TFs exhibit biological activities, which highlight their potential applications in the food, pharmaceutical, and healthcare industries. However, compared to the extensive applications of tea catechins, TFs remain underexploited due to technical challenges in their preparation. A comprehensive understanding of current TFs preparation technologies is essential for the development of novel processing techniques. Scope and approach: This review provides a summary of the formation mechanism of TFs, with an emphasis on the key techniques employed for their extraction and purification. Additionally, it thoroughly examines the impact of synthetic methods and their corresponding influencing factors on TFs synthesis. Recent research advancements in the biological activities of TFs are also discussed succinctly. Key findings and conclusion: Significant advancements in the synthesis, extraction, and purification techniques of TFs have been made in laboratory settings; however, challenges remain in scaling up these processes for mass production and practical applications. Exploring the directional synthetic processes for TFs, developing automated systems for continuous extraction, separation, and concentration, and elucidating the mechanisms underlying the biological activities of different TF monomers should be the focus of future research.
摘要：
Background: The worldwide prevalence of metabolic syndrome (MS) and obesity has led to the exploration of tea consumption as a potential strategy for managing these conditions. However, the clinical outcomes remain debated. We conducted a meta-analysis to evaluate the benefits of tea supplementation in MS and obesity entirely based on randomized controlled trials (RCTs). Methods: Databases of PubMed, Cochrane library, MEDLINE and Web of Science were searched through May 2023 to identify eligible RCTs evaluating the effects of tea supplementation related to MS and obesity. Results were summarized using standardized mean differences (SMDs) by suitable effect model. Results: A total of 24 RCTs were screened, including 1672 subjects from 8 countries. Tea supplementation reduced body weight (BW) (SMD:-0.14; 95%CI:-0.26,-0.03; P = 0.013), body mass index (BMI) (SMD:- 0.15; 95%CI:-0.26,-0.03; P = 0.016), triglycerides (TG) (SMD:-0.21; 95% CI:-0.41,-0.01; P = 0.044), total cholesterol (TC) (SMD:-0.23; 95% CI:-0.44,-0.02; P = 0.033), low-density lipoprotein cholesterol (LDLC) (SMD:-0.28; 95% CI:-0.5,-0.05; P = 0.016) and hemoglobin A1c (HbA1c) (SMD:-0.35; 95% CI:-0.60,- 0.1; P = 0.007) levels, increased high-density lipoprotein (HDL) (SMD: 0.13; 95% CI: 0.01, 0.25; P = 0.04) levels versus Placebo. Conclusion: This meta-analysis presents convincing evidence of the potential advantages of tea consumption for individuals with MS and obesity. Compared with control group, tea consumption can significantly reduce BW, BMI, and lipid profiles (HDL-C, LDL-C, TG, TC) levels of obesity and MS patients. This beneficial effect highlights the prospect of tea as a beneficial dietary strategy in addressing these medical conditions.
摘要：
High levels of free amino acids (AAs) in tea leaves are crucial for tea flavor and health function; however, the dynamic AA biosynthesis, transport, and turnover in tea plants remain elusive. Here we dissected whole tea plants for these dynamics by assessing AA profiles and transcriptomes of metabolic pathway genes in tea roots, stems, and leaves and revealing their distinctive features with regard to AA synthesis, transport, and degradation/recycling. Nitrogen assimilation dominated in the roots wherein glutamine (Gln), theanine, and arginine (Arg) were actively synthesized. Arg was transported into trunk roots and stems, together with Glu, Gln, and theanine as the major AAs in the xylem sap for long-distance root-to-leaf transport. Transcriptome analysis revealed that genes involved in Arg synthesis were highly expressed in roots, but those for Arg transport and degradation were highly expressed in stems and young leaves, respectively. CsGSIa transcripts were found in root meristem cells, root, stem and leaf vascular tissues, and leaf mesophyll where it appeared to participate in AA synthesis, transport, and recycling. Overexpression of CsGSIa in tea transgenic hairy roots and knockdown of CsGSIa in transgenic hairy roots and tea leaves produced higher and lower Gln and theanine than wild-type roots and leaves, respectively. This study provides comprehensive and new insights into AA metabolism and transport in the whole tea plant.
摘要：
Fu brick tea (FBT) has unique "fungal flower" aroma traits, but its source of crucial aroma compounds is still controversial. Aspergillus cristatus is the dominant fungus that participated in the fermentation of FBT. In this study, volatiles of Aspergillus cristatus and corresponding fermented FBT were examined using GC×GC-Q-TOFMS. A total of 59 volatiles were shared by three strains of Aspergillus cristatus isolated from representative FBT. Among them, 1-octen-3-ol and 3-octanone were the most abundant. A total of 133 volatiles were screened as typical FBT volatiles from three FBTs fermented by the corresponding fungi. Aspergillus cristatus and FBT had only 29 coexisting volatiles, indicating that the volatiles of Aspergillus cristatus could not directly contribute to the aroma of FBT. The results of no significant correlation between volatile content in FBT and volatile content in Aspergillus cristatus suggested that intracellular metabolism of Aspergillus cristatus was not a direct driver of FBT aroma formation. Metabolic pathway analysis and proteomic analysis showed that the aroma in FBT was mainly formed by the enzymatic reaction of extracellular enzymes from Aspergillus cristatus. This study enriched our understanding of Aspergillus cristatus in the aroma formation process of FBT.
